Manual of style
/File/en/Klipper.png
To Do
Glossary, Punctuation
OpenTTD Development Documentation
External Links

OpenTTD GitHub
Contributing to OpenTTD - guidelines
OpenTTD Doxygen

General Reference

Coding style
Compiling OpenTTD
Debugging
Add a setting
Add a squirrel function
Understanding the SaveGame handler
Bumping the savegame version
Doing an OpenTTD release

Language and Strings

Manual of style
Format of langfiles
Using OpenTTD strings
List of special strings

Window System

Using the window system
Colour codes that exist in OpenTTD
Adding a text box
Understanding the widget focus system
GUI style guide

Multiplayer

The OpenTTD TCP protocol
The OpenTTD UDP protocol
Debugging desyncs
Server Admin Port development

Ingame Console

The console window
Console commands
Console variables
Using console scripting
Adding functions/commands to the console
Adding variables to the console
Console development history

Content APIs (modding frameworks)

Graphics and similar (NewGRF)
AI framework (NoAI)
GameScript framework (NoGO)

Other Reference

Map array (landscape grid)
Vehicles
Pathfinding
Train acceleration

Welcome to the OpenTTD Manual of Style. This document keeps the rules for all English in-game text (both of UK and US variants). This manual was first started with the goal of improving the text quality of the UI tooltips, as to make localization to different languages easier. Eventually this evolved into a full documentation project to unify in-game written-text rules, fix inconsistencies, and improve readability.

The OpenTTD Manual of Style is modeled after the Microsoft Writing Style Guide. Additional formatting unique to OpenTTD was sourced from community preferences or was taken from text already present in the original UI.

Contents

Scope

Quick reference guide

This is a summary of the most important rules for proofreaders to use as cheat-sheet when reviewing text. Be sure to read the entire style guide before starting revision as to clear any doubts.

Language style

Bias-free communication

Because OpenTTD is played by many people across the globe, the language employed must be as inclusive as possible. Here are the key guidelines for bias-free communication.

Correct You can host a game via the multiplayer screen.
Incorrect A user can host a game via the multiplayer screen.
Use this Not this
chair chairman
workforce, staff manpower
operates mans

Descriptive texts and UI labels

The OpenTTD UI is populated with text in two main formats with unique rules of their own: descriptive texts and UI labels.

Descriptive texts

Tooltips are an example of descriptive texts.

UI labels

Some examples of UI labels: field and button labels.

Acronyms

Using acronyms is often a popular choice for making texts easier to read or for saving space in the UI. Some acronyms are widely understood and sometimes preferred over the terms they represent, but others may cause confusion to people who aren't familiarized with them. Keep in mind the following guidelines when using acronyms:

Correct If you have any doubts check our FAQ.
Incorrect If you have any doubts check our Faq.
Correct The Dash is a diesel multiple unit (DMU) available from 1984.
Incorrect The Dash is a DMU available from 1984.
Correct BaNaNaS is the content downloader for OpenTTD.
Incorrect BANANAS is the content downloader for OpenTTD.

Capitalization

Rules for capitalization determine the use of capital letter within written text. They help improve how the text reads and how it looks.

General capitalization rules

Follow these base guidelines when capitalizing texts:

Correct The eGRVTS is a newgrf vehicle set by Zephyris.
Incorrect eGRVTS is a newgrf vehicle set by Zephyris.
Correct You can download OpenTTD on the link below.
Incorrect You can download OpenTTD HERE.
Correct You can check our email address in the contacts section.
Incorrect You can check our eMail address in the contacts section.
Correct The electric multiple unit (EMU) is a type of train.
Incorrect The Electric Multiple Unit (EMU) is a type of train.

Capitalization styles

There are two types of capitalization used in interface texts for OpenTTD, sentence and title capitalization.

Sentence capitalization

Example (prompt text) Are you sure you want to exit OpenTTD and return to Unix?
Use sentence capitalization in:
Example (tooltip) Start playing on a new map.
Example (button) New game
Example Section 1 - How to play
Example Build railway station: For loading and unloading cargo or passengers.
Example Operating profits graph

Title capitalization

Example (title) OpenTTD Scenario Editor
Use title capitalization in:
Example 1 Station accepts: Coal, Iron Ore, Goods
Example 2 Engine type: Diesel
Example Kirby Paul Tank
Example Yen, Dollar, Euro
Example Wartington Coal Mine
Example Jazz Jukebox
Example Burnley & Smiths Inc.
Example Chief Executive Officer
Example Ctrl+Click+Drag to select an area

Formatting

Descriptive texts

General descriptive text formatting

Headings

Headings are used to name documents and to separate them into sections. They are a form of internal organization in written text. Follow these guidelines when formatting headings:

Correct 1 - What's new
Correct 1 - What's new?
Incorrect 1 - What's new.

Key names and shortcuts

These are compound terms that indicate one or a combination of keys and mouse actions used to perform game functions without using interface buttons. Follow these guidelines when writing key names and shortcuts:

Correct Ctrl+Click+Drag selects the area diagonally.
Incorrect Ctrl, Click and Drag selects the area diagonally.

Titles

Titles refer to names of individual works (books, songs, apps, articles, etc). Follow these guidelines when formatting titles appearing in-game:

Example 1 Jazz Jukebox
Example 2 OpenTTD Scenario Editor
Example OpenTTD Manual of Style
Example For more information see section 9 "How to play".
Example Playing song 1 - Taxi Ride

Tooltips

Elements of a tooltip: Green - title; red - description; blue - additional shortcuts.

Tooltips are texts printed in small pop-up windows that appear when you hover the mouse cursor over certain UI functions. They are a large part of the OpenTTD descriptive texts. Tooltips can be composed by one or more of three possible parts:

The following general formatting rules are applied to tooltips:

Buttons with icons tooltips

If a tooltip is associated with an icon button the following rules apply:

Icon button tooltips always require a title on the first line.

Buttons with text tooltips

If a tooltip is associated with a text button the following rules apply:

A text button tooltip. The button label acts as a title.

Table tooltips

If a tooltip is associated with a table the following rules apply:

If a table has a title or does not share a window with other tables, then the tooltip requires a description only.

UI labels

General UI label formatting

Numbers

General formatting rules for numbers

Follow these base guidelines when writing numbers:

Correct One bus is all that is necessary to start a simple passenger route between two stops.
Incorrect 1 bus is all that is necessary to start a simple passenger route between two stops.
Correct Places a section of rail in one direction.
Correct View finances for 4-Rail Inc.
Incorrect Places a section of rail in 1 direction.
Correct There are 15 trains, followed by 5 trains, followed by 1 train.
Incorrect There are 15 trains, followed by five trains, followed by one train.

Numerals

Use numerals (not spelled out) in the following instances:

Example Max. speed: 100 km p/h
Example 1 5 units of coal
Example 2 Press key 4
Example It takes 5% of the total value.
Example Page 5, Chapter 1

Ordinals

Correct If this is the first time playing OpenTTD, check out the manual.
Incorrect If this is the 1st time playing OpenTTD, check out the manual.
Correct 3rd Mar 1982
Correct The 20th century
Incorrect The twentieth century

Writing

General writing tips

Preferable (tooltip) Places a railway bridge over land or water.
Avoid (tooltip) Constructs a railway bridge over land or water.

Tooltips

Preferable Demolish: Clears all objects in a selected area. Ctrl+Click+Drag selects the area diagonally.
Avoid Demolish: Use this tool to clear all objects in an area. Ctrl+Click+Drag selects the area diagonally.
Correct Build canals: Places a navigable waterway on flat land.
Incorrect Build canals: Places a navigable canal on flat land.
Correct Pause game
Incorrect Pause button: Pauses the game.
Example 1 Build road: Places a section of road in a single direction.
Example 2 Build road: Place a section of road in a single direction.
Correct Music & sound
Incorrect Music and sound
Correct Ctrl+Click+Drag selects an area. Shift+Click shows price preview.
Incorrect Ctrl+Click+Drag selects an area, and Shift+Click shows price preview.

UI labels

Correct Save & quit
Incorrect Save and quit